Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Answer:
A
B
C
Step-by-step explanation:
I think this is correct
Answer:
Step-by-step explanation:
Answer:
Step-by-step explanation:Worked out on paper shown below
Also I recommended a online app called (it has wierd name but it’s helpful for algebra) mathpapa
Also I do math in pen so the last answer is messed up it’s 4c^2d and then the rest of the parentheses.Sorry for that.